α‐Carbonyl Cations in Sulfoxide‐Driven Oxidative Cyclizations

Angewchem
α‐Carbonyl Cations in Sulfoxide‐Driven Oxidative Cyclizations: The selective, metal‐free generation of α‐carbonyl cations from simple internal alkynes was accomplished by the addition of a sulfoxide to a densely substituted vinyl cation. The high reactivity of the...

Pd‐PEPPSI‐IPent‐SiO2: A Supported Catalyst for Challenging Negishi Coupling Reactions in Flow

Angewchem
Pd‐PEPPSI‐IPent‐SiO2: A Supported Catalyst for Challenging Negishi Coupling Reactions in Flow: A silica‐supported precatalyst, Pd‐PEPPSI‐IPent‐SiO2, has been prepared and evaluated for its proficiency in the Negishi cross‐coupling of hindered and electronically deactivated coupling partners. The...

Catalytic C(sp3)–H Alkylation via an Iron Carbene Intermediate

Jacs
Catalytic C(sp3)–H Alkylation via an Iron Carbene Intermediate: The catalytic transformation of a C(sp3)–H bond to a C(sp3)–C bond via an iron carbene intermediate represents a long-standing challenge. Despite the success of enzymatic and small molecule iron catalysts mediating challenging C(sp3)–H oxidations and aminations via high-valent iron oxos and nitrenes, C(sp3)–H alkylations via isoelectronic iron carbene intermediates have thus far been unsuccessful. Iron carbenes have been inert, or shown to favor olefin cyclopropanation and heteroatom-hydrogen insertion. Herein we report an iron phthalocyanine-catalyzed alkylation of allylic and benzylic C(sp3)–H bonds.

Enantioselective Synthesis of Cyclobutenes by Intermolecular [2 2] Cycloaddition with Non-C2 Symmetric Digold Catalysts

Jacs
Enantioselective Synthesis of Cyclobutenes by Intermolecular [2 2] Cycloaddition with Non-C2 Symmetric Digold Catalysts: The enantioselective intermolecular gold(I)-catalyzed [2+2] cycloaddition of terminal alkynes and alkenes has been achieved using non-C2-chiral Josiphos digold(I) complexes as catalysts, by the formation of the monocationic complex. This new approach has been applied to the enantioselective total synthesis of rumphellaone A.

Intermolecular Radical Addition to Carbonyls Enabled by Visible Light Photoredox Initiated Hole Catalysis

Jacs
Intermolecular Radical Addition to Carbonyls Enabled by Visible Light Photoredox Initiated Hole Catalysis: Herein, we present a novel strategy for the utilization of simple carbonyl compounds, aldehydes and ketones, as intermolecular radical acceptors. The reaction is enabled by visible light photoredox initiated hole catalysis and the in situ Brønsted acid activation of the carbonyl compound.

Branched-Selective Intermolecular Ketone α-Alkylation with Unactivated Alkenes via an Enamide Directing Strategy

Jacs
Branched-Selective Intermolecular Ketone α-Alkylation with Unactivated Alkenes via an Enamide Directing Strategy: We describe a strategy for intermolecular branched-selective α-alkylation of ketones using simple alkenes as the alkylating agents. Enamides derived from isoindolin-1-one provide an excellent directing template for catalytic activation of ketone α-positions.

Total Synthesis of (−)-Nahuoic Acid Ci (Bii)

Total Synthesis of (−)-Nahuoic Acid Ci (Bii): A convergent total synthesis of (−)-nahuoic acid Ci(Bii) (3), a novel cis-decalin polyketide, has been achieved. Key synthetic transformations include Type II Anion Relay Chemistry (ARC) to construct the polyol chain, a Ti-catalyzed asymmetric Diels–Alder reaction to generate the cis-decalin skeleton, and a late-stage large fragment union exploiting a Micalizio alkoxide-directed alkyne–alkene coupling tactic.

Catalytic Carbonylative Rearrangement of Norbornadiene via Dinuclear Carbon–Carbon Oxidative Addition

Jacs
Catalytic Carbonylative Rearrangement of Norbornadiene via Dinuclear Carbon–Carbon Oxidative Addition: Single bonds between carbon atoms are inherently challenging to activate using transition metals; however, ring-strain release can provide the necessary thermodynamic driving force to make such processes favorable. In this report, we describe a strain-induced C–C oxidative addition of norbornadiene.

Photoredox Imino Functionalizations of Olefins

Angewchem
Photoredox Imino Functionalizations of Olefins: Shown herein is that polyfunctionalized nitrogen heterocycles can be easily prepared by a visible‐light‐mediated radical cascade process. This divergent strategy features the oxidative generation of iminyl...

Stereoselective Synthesis of Z Fluoroalkenes through Copper‐Catalyzed Hydrodefluorination of gem‐Difluoroalkenes with Water

Angewchem
Stereoselective Synthesis of Z Fluoroalkenes through Copper‐Catalyzed Hydrodefluorination of gem‐Difluoroalkenes with Water: A copper catalytic system was established for the stereoselective hydrodefluorination of gem‐difluoroalkenes through C−F activation to synthesize various Z fluoroalkenes. H2O is used as the hydrogen source...

Enantioselective Direct Mannich‐Type Reactions Catalyzed by Frustrated Lewis Acid/Brønsted Base Complexes

Angewchem
Enantioselective Direct Mannich‐Type Reactions Catalyzed by Frustrated Lewis Acid/Brønsted Base Complexes: An enantioselective direct Mannich‐type reaction catalyzed by a sterically frustrated Lewis acid/Brønsted base complex is disclosed. Cooperative functioning of the chiral Lewis acid and achiral Brønsted...

Copper‐Catalyzed C(sp3)−H/C(sp3)−H Cross‐Dehydrogenative Coupling with Internal Oxidants: Synthesis of 2‐Trifluoromethyl‐Substituted Dihydropyrrol‐2‐ols

Angewchem
Copper‐Catalyzed C(sp3)−H/C(sp3)−H Cross‐Dehydrogenative Coupling with Internal Oxidants: Synthesis of 2‐Trifluoromethyl‐Substituted Dihydropyrrol‐2‐ols: The first oxidative C(sp3)−H/C(sp3)−H cross‐dehydrogenative coupling (CDC) reaction promoted by an internal oxidant is reported. This copper‐catalyzed CDC reaction of oxime acetates and trifluoromethyl...

Buchwald–Hartwig Amination of Nitroarenes

Angewchem
Buchwald–Hartwig Amination of Nitroarenes: The Buchwald–Hartwig amination of nitroarenes was achieved for the first time by using palladium catalysts bearing dialkyl(biaryl)phosphine ligands. These cross‐coupling reactions of nitroarenes with diarylamines,...

Regio‐ and Stereoselective Chlorocyanation of Alkynes

Angewchem
Regio‐ and Stereoselective Chlorocyanation of Alkynes: A variety of terminal and internal alkynes were converted regio‐ and stereoselectively into (Z)‐3‐chloroacrylonitriles by treatment with BCl3 in the presence of stoichiometric amounts of imidazolium thiocyanates....

Total Synthesis of Unsymmetrically Oxidized Nuphar Thioalkaloids via Copper-Catalyzed Thiolane Assembly

Jacs
Total Synthesis of Unsymmetrically Oxidized Nuphar Thioalkaloids via Copper-Catalyzed Thiolane Assembly: An asymmetric total synthesis of (+)-6-hydroxythiobinupharidine (1b) and (−)-6-hydroxythionuphlutine (2b), a set of hemiaminal containing dimeric sesquiterpenes isolated from yellow water lilies of the Nuphar genus, is described. The central bis-spirocyclic tetrahydrothiophene ring was forged through the Stevens rearrangement of a sulfonium ylide, generated in situ from the coupling of a copper-carbene with a spirocyclic thietane.

Visible-Light-Promoted C–S Cross-Coupling via Intermolecular Charge Transfer

Jacs
Visible-Light-Promoted C–S Cross-Coupling via Intermolecular Charge Transfer: Disclosed is a mild, scalable, visible-light-promoted cross-coupling reaction between thiols and aryl halides for the construction of C–S bonds in the absence of both transition metal and photoredox catalysts. The scope of aryl halides and thiol partners includes over 60 examples and therefore provides an entry point into various aryl thioether building blocks of pharmaceutical interest.

Remote Migratory Cross-Electrophile Coupling and Olefin Hydroarylation Reactions Enabled by in Situ Generation of NiH

Jacs
Remote Migratory Cross-Electrophile Coupling and Olefin Hydroarylation Reactions Enabled by in Situ Generation of NiH:A highly efficient strategy for remote reductive cross-electrophile coupling has been developed through the ligand-controlled nickel migration/arylation. This general protocol allows the use of abundant and bench-stable alkyl bromides and aryl bromides for the synthesis of a wide range of structurally diverse 1,1-diarylalkanes in excellent yields and high regioselectivities under mild conditions.

Alkynyl Thioethers in Gold‐Catalyzed Annulations to form Oxazoles

Angewchem
Alkynyl Thioethers in Gold‐Catalyzed Annulations to form Oxazoles: Non‐oxidative, regioselective, and convergent access to densely functionalized oxazoles is realized in a functional‐group tolerant manner using alkynyl thioethers. Sulfur‐terminated alkynes provide access...

Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4‐Dioxane

Angewchem
Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4‐Dioxane: A practical method for radical chain reduction of various aryl bromides and chlorides is introduced. The thermal process uses NaH and 1,4‐dioxane as reagents and 1,10‐phenanthroline as an initiator. Hydrodehalogenation...

Iron‐Catalyzed anti‐Selective Carbosilylation of Internal Alkynes

Angewchem
Iron‐Catalyzed anti‐Selective Carbosilylation of Internal Alkynes: Reported is the anti‐selective carbosilylation of internal alkynes with silylborane and alkyl halides using a FeBr2/DPPE catalyst system. The iron catalyst allows simultaneous introduction of a carbon...

Meta‐Selective C−H Borylation of Benzylamine, Phenethylamine and Phenylpropylamine‐Derived Amides Enabled by a Single Anionic Ligand

Angewchem
Meta‐Selective C−H Borylation of Benzylamine, Phenethylamine and Phenylpropylamine‐Derived Amides Enabled by a Single Anionic Ligand: Selective functionalization at the meta position of arenes remains a significant challenge. In this work, we demonstrate that a single anionic bipyridine ligand bearing a remote sulfonate group enables...

Exploiting a “Beast” in Carbenoid Chemistry: Development of a Straightforward Direct Nucleophilic Fluoromethylation Strategy

Jacs
Exploiting a “Beast” in Carbenoid Chemistry: Development of a Straightforward Direct Nucleophilic Fluoromethylation Strategy: The first direct and straightforward nucleophilic fluoromethylation of organic compounds is reported. The tactic employs a “fleeting” lithium fluorocarbenoid (LiCH2F) generated from commercially available fluoroiodomethane. Precise reaction conditions were developed for the generation and synthetic exploitation of such a labile species. The versatility of the strategy is showcased in ca. 50 examples involving a plethora of electrophiles.

Modular, Scalable Synthesis of Group A Streptogramin Antibiotics

Jacs
Modular, Scalable Synthesis of Group A Streptogramin Antibiotics: Streptogramin antibiotics are used clinically to treat multidrug-resistant bacterial infections, but their poor physicochemical properties and narrow spectra of activity have limited their utility. New methods to chemically modify streptogramins would enable structural optimization to overcome these limitations as well as to combat growing resistance to the class. Here we report a modular, scalable synthesis of group A streptogramin antibiotics that proceeds in 6–8 linear steps from simple chemical building blocks.

Copper-Catalyzed Enantioselective Hydroboration of Unactivated 1,1-Disubstituted Alkenes

Jacs
Copper-Catalyzed Enantioselective Hydroboration of Unactivated 1,1-Disubstituted Alkenes: We report an efficient and highly enantioselective hydroboration of aliphatic 1,1-disubstituted alkenes with pinacolborane using a phosphine-Cu catalyst. The method allows facile preparation of enantiomerically enriched β-chiral alkyl pinacolboronates from a range of 1,1-disubstituted alkenes with high enantioselectivity up to 99% ee.

Catalytic Enantioselective Synthesis of Highly Functionalized Difluoromethylated Cyclopropanes

Angewchem
Catalytic Enantioselective Synthesis of Highly Functionalized Difluoromethylated Cyclopropanes: The first catalytic asymmetric synthesis of highly functionalized difluoromethylated cyclopropanes is described. The method, based on a rhodium‐catalyzed cyclopropanation of difluoromethylated olefins,...

Copper‐Catalyzed Borylacylation of Activated Alkenes with Acid Chlorides

Angewchem
Copper‐Catalyzed Borylacylation of Activated Alkenes with Acid Chlorides: A method for the copper‐catalyzed borylacylation of activated alkenes is presented. The reaction involves borylcupration of the alkene, followed by capture of the generated alkyl–copper intermediate with...

Carboxylation of Aromatic and Aliphatic Bromides and Triflates with CO2 by Dual Visible‐Light–Nickel Catalysis

Angewchem
Carboxylation of Aromatic and Aliphatic Bromides and Triflates with CO2 by Dual Visible‐Light–Nickel Catalysis: We report the efficient carboxylation of bromides and triflates with K2CO3 as the source of CO2 in the presence of an organic photocatalyst in combination with a nickel complex under visible light irradiation...

Divergent C–H Annulation for Multifused N‐Heterocycles: Regio‐ and Stereospecific Cyclizations of N‐Alkynylindoles

Angewchem
Divergent C–H Annulation for Multifused N‐Heterocycles: Regio‐ and Stereospecific Cyclizations of N‐Alkynylindoles: N‐Alkynylindoles were divergently cyclized for the synthesis of multifused N‐heterocycles. An ortho‐aryl palladium species was added to the α position of an ynamine to generate (Z)‐6‐alkylidene/benzylidene‐6H‐isoindolo[2,1‐a]indoles,...

Catalytic Reductive Pinacol‐Type Rearrangement of Unactivated 1,2‐Diols through a Concerted, Stereoinvertive Mechanism

Jacs
Catalytic Reductive Pinacol‐Type Rearrangement of Unactivated 1,2‐Diols through a Concerted, Stereoinvertive Mechanism: A catalytic pinacol‐type reductive rearrangement reaction of internal 1,2‐diols is reported herein. Several scaffolds not usually amenable to pinacol‐type reactions, such as aliphatic secondary–secondary...

Total Synthesis of Crocagin A

Angewchem
Total Synthesis of Crocagin A: Crocagin A (1) combines an attractive molecular structure with an unusual biosynthesis and bioactivity. An efficient synthesis of crocagin A is presented that hinges on an early formation of the heterotricyclic...

Cross‐Coupling of α‐Carbonyl Sulfoxonium Ylides with C−H Bonds

Angewchem
Cross‐Coupling of α‐Carbonyl Sulfoxonium Ylides with C−H Bonds: The functionalization of carbon–hydrogen bonds in non‐nucleophilic substrates using α‐carbonyl sulfoxonium ylides has not been so far investigated, despite the potential safety advantages that such reagents...

Divergent Reactivity of a Dinuclear (NHC)Nickel(I) Catalyst versus Nickel(0) Enables Chemoselective Trifluoromethylselenolation

Angewchem
Divergent Reactivity of a Dinuclear (NHC)Nickel(I) Catalyst versus Nickel(0) Enables Chemoselective Trifluoromethylselenolation: We herein showcase the ability of NHC‐coordinated dinuclear NiI–NiI complexes to override fundamental reactivity limits of mononuclear (NHC)Ni0 catalysts in cross‐couplings. This is demonstrated with the...

Electrochemically Enabled, Nickel‐Catalyzed Amination

Angewchem
Electrochemically Enabled, Nickel‐Catalyzed Amination: Along with amide bond formation, Suzuki cross‐coupling, and reductive amination, the Buchwald–Hartwig–Ullmann‐type amination of aryl halides stands as one of the most employed reactions in modern medicinal...

Palladium‐Catalyzed [3 3] Annulation of Vinyl Chromium(0) Carbene Complexes through Carbene Migratory Insertion/Tsuji–Trost Reaction

Angewchem
Palladium‐Catalyzed [3 3] Annulation of Vinyl Chromium(0) Carbene Complexes through Carbene Migratory Insertion/Tsuji–Trost Reaction: Vinyl chromium(0) Fischer carbene complexes were employed as the source of π‐allylic palladium species for catalytic [3+3] annulation under palladium catalysis. Mechanistically, this transformation is...

Ligand‐Controlled Regiodivergent and Enantioselective Copper‐Catalyzed Hydroallylation of Alkynes

Angewchem
Ligand‐Controlled Regiodivergent and Enantioselective Copper‐Catalyzed Hydroallylation of Alkynes: A ligand‐controlled regiodivergent and enantioselective copper‐catalyzed intermolecular hydroallylation of alkynes with allylic phosphates and hydrosilanes has been achieved for the first time. The chiral...

Nickel‐Catalyzed Reductive Allylation of Tertiary Alkyl Halides with Allylic Carbonates

Angewchem
Nickel‐Catalyzed Reductive Allylation of Tertiary Alkyl Halides with Allylic Carbonates: The construction of all C(sp3) quaternary centers has been successfully achieved under Ni‐catalyzed cross‐electrophile coupling of allylic carbonates with unactivated tertiary alkyl halides. For allylic...

Synthesis of Phenalenyl‐Fused Pyrylium Cations: Divergent C−H Activation/Annulation Reaction Sequence of Naphthalene Aldehydes with Alkynes

Angewchem
Synthesis of Phenalenyl‐Fused Pyrylium Cations: Divergent C−H Activation/Annulation Reaction Sequence of Naphthalene Aldehydes with Alkynes: Described herein is the synthesis of stable oxonium‐doped polycyclic aromatic hydrocarbons (PAHs) by the rhodium‐catalyzed C−H activation/annulations of naphthalene‐type aldehydes with internal alkynes....

Direct and Stereospecific [3 2] Synthesis of Pyrrolidines from Simple Unactivated Alkenes

Angewchem
Direct and Stereospecific [3 2] Synthesis of Pyrrolidines from Simple Unactivated Alkenes: Pyrrolidines are important heterocyclic compounds with endless applications in organic synthesis, metal catalysis, and organocatalysis. Their potential as ligands for first‐row transition‐metal catalysts...

Review: Enantioselective Access to Robinson Annulation Products and Michael Adducts as Precursors

Angewchem
Enantioselective Access to Robinson Annulation Products and Michael Adducts as Precursors: The Robinson annulation is a reaction that has been useful for numerous syntheses since its discovery in 1935, especially in the field of steroid synthesis. The products are usually obtained after three...

Titanocene‐Catalyzed Radical Opening of N‐Acylated Aziridines

Angewchem
Titanocene‐Catalyzed Radical Opening of N‐Acylated Aziridines: Aziridines activated by N‐acylation are opened to the higher substituted radical through electron transfer from titanocene(III) complexes in a novel catalytic reaction. This reaction is applicable in conjugate...

Reagent‐Free C−H/N−H Cross‐Coupling: Regioselective Synthesis of N‐Heteroaromatics from Biaryl Aldehydes and NH3

Angewchem
Reagent‐Free C−H/N−H Cross‐Coupling: Regioselective Synthesis of N‐Heteroaromatics from Biaryl Aldehydes and NH3: An unprecedented synthesis of N‐heteroaromatics from biaryl aldehydes and NH3 through reagent‐free C−H/N−H cross‐coupling has been developed. The electrosynthesis uses NH3 as an inexpensive and atom‐economic...

Stereoselective Total Synthesis of Bisorbicillinoid Natural Products by Enzymatic Oxidative Dearomatization/Dimerization

Angewchem
Stereoselective Total Synthesis of Bisorbicillinoid Natural Products by Enzymatic Oxidative Dearomatization/Dimerization: Natural products are a virtually inexhaustible source of small molecules with spectacular molecular architectures and biomedical potential. Their structural complexity generates formidable challenges to...

Nickel‐Catalyzed Conjugate Addition of Silyl Ketene Imines to In Situ Generated Indol‐2‐ones: Highly Enantioselective Construction of Vicinal All‐Carbon Quaternary Stereocenters

Angewchem
Nickel‐Catalyzed Conjugate Addition of Silyl Ketene Imines to In Situ Generated Indol‐2‐ones: Highly Enantioselective Construction of Vicinal All‐Carbon Quaternary Stereocenters: The first enantioselective conjugate addition of silyl ketene imines to in situ generated indol‐2‐ones was performed in the presence of a chiral N,N′‐dioxide/NiII catalyst. This method provides efficient...

Anion–π Catalysis of Diels–Alder Reactions

Angewchem
Anion–π Catalysis of Diels–Alder Reactions: Among concerted cycloadditions, the Diels–Alder reaction is the grand old classic, which is usually achieved with acid catalysis. In this report, hydroxypyrones, oxa‐, and thiazolones are explored because...

Enantioselective Total Synthesis of (−)-Pavidolide B

Jacs
Enantioselective Total Synthesis of (−)-Pavidolide B: The enantioselective synthesis of (−)-pavidolide B (1) was achieved in a linear sequence of 10 steps. The key steps are (a) an enantioselective organocatalytic cyclopropanation; (b) a radical-based cascade annulation for the regio- and diastereo-selective synthesis of the highly functionalized lactone 3 bearing the characteristic tricyclic core and seven contiguous stereocenters....

Expedient Synthesis of 1,5-Diketones by Rhodium-Catalyzed Hydroacylation Enabled by C–C Bond Cleavage

Jacs
Expedient Synthesis of 1,5-Diketones by Rhodium-Catalyzed Hydroacylation Enabled by C–C Bond Cleavage: A rhodium-catalyzed intermolecular hydroacylation reaction of vinyl cyclobutanols with non-chelating aldehydes has been developed. This reaction offers a new and atom-economical approach for the selective preparation of 1,5-diketones in high yields.

Synthesis of Bicyclo[n.1.0]alkanes by a Cobalt‐Catalyzed Multiple C(sp3)−H Activation Strategy

Angewchem
Synthesis of Bicyclo[n.1.0]alkanes by a Cobalt‐Catalyzed Multiple C(sp3)−H Activation Strategy: A cobalt‐catalyzed dual C(sp3)−H activation strategy has been developed and it provides a novel strategy for the synthesis of bicyclo[4.1.0]heptanes and bicyclo[3.1.0]hexanes. A key to the success of this...

Synthesis of Polyfunctional Diorganomagnesium and Diorganozinc Reagents through In Situ Trapping Halogen–Lithium Exchange of Highly Functionalized (Hetero)aryl Halides in Continuous Flow

Angewchem
Synthesis of Polyfunctional Diorganomagnesium and Diorganozinc Reagents through In Situ Trapping Halogen–Lithium Exchange of Highly Functionalized (Hetero)aryl Halides in Continuous Flow: We report a halogen–lithium exchange performed in the presence of various metal salts (ZnCl2, MgCl2⋅LiCl) on a broad range of sensitive bromo‐ or iodo(hetero)arenes using BuLi or PhLi as the exchange reagent...

Synthesis of [18F]Fluoroarenes by Nucleophilic Radiofluorination of N‐Arylsydnones

Angewchem
Synthesis of [18F]Fluoroarenes by Nucleophilic Radiofluorination of N‐Arylsydnones: A practical method for radiofluorination of anilines with [18F]fluoride via N‐arylsydnone intermediates is described. These precursors are stable, easy to handle and facilitate direct and regioselective...

Selective Palladium‐Catalyzed Allenic C−H Bond Oxidation for the Synthesis of [3]Dendralenes

Angewchem
Selective Palladium‐Catalyzed Allenic C−H Bond Oxidation for the Synthesis of [3]Dendralenes: A highly selective palladium‐catalyzed allenic C−H bond oxidation was developed, and it provides a novel and straightforward synthesis of [3]dendralene derivatives. A variety of [3]dendralenes with diverse...

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